The study is designed to determine the effect of shunting from the portal blood system to the systemic blood system on kidney function and on the accumulation of fluid in the body. The TIPS procedure is being done to help control the fluid collecting in the abdomen or to control bleeding from varices in the esophagus or stomach. Since liver disease can lead to worsening kidney function and the collection of sodium and water in the body, we wish to investigate what role the decreased pressure in the portal system has on kidney function.